If Joe Biden gets into the presidential race, allies and supporters of Hillary Clinton say there are just two words that will make a difference as he seeks support among women and African-Americans: Anita Hill.

Nearly 24 years have passed since the confirmation hearings for Supreme Court nominee Clarence Thomas in which Hill, a respected law professor, was grilled under oath about alleged inappropriate sexual behavior by Thomas, her former boss. The graphic testimony gripped Washington and the country and spurred intense public conversations about sex, harassment and the nominee's charge of being subjected to a "high-tech lynching for uppity blacks.''

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Biden's done a lot over the past 24 years, including authoring the landmark Violence Against Women Act and leading its four reauthorizations. But that hasn't erased the memories of how Biden presided over those hearings as chairman of the Senate Judiciary Committee, blamed for doing little to stop the attacks on Hill and opting not to call three other witnesses who would have echoed Hill's charges of sexual harassment. Biden almost apologetically gave Thomas the benefit of the doubt, critics say, and that stance helped put Thomas on the Supreme Court.

Ever since, for many women and blacks, Hill's name conjures an image of a black woman struggling under attack by a dozen powerful white men asking aggressive questions and questioning her character.

If Biden decides to run for president, his path to the Democratic nomination requires him to stand in the way of the woman who could be the first female president — and issues of sex and gender will be on the table whether either side likes it or not.

Moreover, Biden's campaign strategy, if he decides to run, will hinge on the South Carolina primary, where African-Americans make up enough of the Democratic electorate to decide the winner. And he'll need to capture a significant share of the black vote in other states as well to have a chance in what would likely be a long and tough fight for Democrats through next spring.

Dredging up what was seen as Biden's subjecting an African-American woman to public humiliation and abuse could erode his support among women and blacks. And raising the question of whether he can be blamed for the confirmation of Thomas — now one of the most rigidly conservative members of the high court — has the potential to cut at the vice president's support among Democrats more broadly, especially with Clinton now making a regular talking point of her prediction that the next president might have up to three Supreme Court appointments.

Biden has expressed regrets about the hearings but has never apologized for them, as many Hill supporters and others wanted. He's acknowledged that he was wary of the racial dynamics involved. He's said that calling those witnesses might have killed Thomas' nomination. He and aides admit that they didn't anticipate the degree to which Republicans would target Hill personally and that they were outplayed politically.

Still, Biden believes the hearings accomplished a greater good. Last Thursday night, speaking to a rally against campus sexual assault at The Ohio State University, Biden brought up his role in the 1991 hearings in an unprompted aside, proudly taking credit for helping change America's attitudes toward sexual harassment by bringing the issue to the forefront.

''During the Clarence Thomas hearings, one of the things that emerged was the issue of sexual harassment,'' Biden said. "It was the thing that no one wanted to touch. I remember saying to my colleagues, 'This is so much bigger than a single judge.' Because of the national debate on that issue, men may still do it … but it's a different place.''

This is not how Hill and others who still stand with her see what happened during those weeks in 1991.

Biden did “a disservice to me, a disservice more importantly, to the public,” Hill said in an interview last spring with The Huffington Post. Calling the other witnesses could have “helped the public to understand sexual harassment. He failed to do that.”

Hill declined a request to elaborate for this story. But Kit Smith, a founding member of the South Carolina-based I Believe Anita Hill group, said she was surprised by Biden's comments last week. “I guess the best defense is a good offense. He's trying to show, 'I'm a hero,' before anybody can say, 'You screwed up.'”

Smith said she's dismayed by the possibility that Biden might run against Clinton. In her view, the vice president actually set back efforts to curb sexual harassment by allowing Hill's motives and truthfulness to be questioned. “'She was the one who ended up losing and being maligned,” Smith said. ''That's what's held us back all these years, because women are afraid they're going to be made fun of, they're going to be maligned.'”

(Data from the Equal Employment Opportunity Commission — which, somewhat ironically, Thomas chaired during the time he worked with Hill — do not support this. Year by year after the hearings, reports of sexual harassment skyrocketed, though there is obviously no way to make a direct link to the hearings or to Biden's performance during them.)

Charles Ogletree, the Harvard Law School professor who represented Hill (and once had President Barack Obama as a student), said he's still mad about how Biden handled himself back then.

“I was shocked and dismayed that Joe Biden was asking questions that didn't seem appropriate and was not in her corner as a Democrat,” Ogletree said. “The point is that he's supposed to be neutral, but his questions to Anita Hill were as piercing as anyone's.”

Ogletree said he's brought up the hearings with Biden in the years since, but hasn't been satisfied with the response. “He's said that this job was to control the hearing, that he was surprised by the result as well,” Ogletree said.

Ogletree said that Hill, with whom he's become friends, has never spoken with Biden or any of the other senators since the hearing.

''What changed the national approach was people's horror at what [Thomas] had done,'' said Susan Deller Ross, another of Hill's lawyers, who's now a professor at Georgetown Law Center. Ross is also supporting Clinton.

The Clinton campaign says it wants nothing to do with any of this. Clinton spokesman Jesse Ferguson called attempts to raise the Hill hearings against Biden “a trumped-up story intended to spark a fight. Of course we wouldn't do that.'' Ferguson reiterated the campaign's standard line that Biden deserves however much time and space he needs to make a decision about 2016.

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However, Clinton allies would have deep resources to draw from if they choose to use Hill to attack Biden. Among them: the “Anita” documentary that showcases Biden's role; Hill and Ogletree have been traveling the country to attend screenings. “Sexual harassment is a serious matter,” Biden can be heard saying at the hearing right after the opening credits.

Another factor is Clinton ally David Brock, who, long before he founded the leftist Media Matters, was a conservative journalist and author of ''The Real Anita Hill.'' He's since disavowed the 1993 book, which claimed to get at her true motives for testifying against Thomas, but he hasn't forgotten the research that produced it: Among the emails revealed from Clinton's server is a 2010 memo he wrote, forwarded to Clinton by confidant Sid Blumenthal, ''on Impeaching Clarence Thomas'' (based on new information from a witness who, Brock says, can show the nominee lied under oath).

Biden has defenders. One of them is Cynthia Hogan, who served as his counsel on the Judiciary Committee at the time, with responsibilities that included leading the deposition of Angela Wright, the witness most observers think had the most potential to derail Thomas' confirmation. At the root of criticism of Biden is a fundamental misunderstanding, she says.

''The Judiciary Committee and the Senate at large are not like a court of law. You don't have a judge who sits there and controls everything,'' Hogan says. ''Instead, each senator has the right to make his or her own point of view heard. Then-Sen. Biden felt that he had an obligation to try to sit in a neutral position as chair, and that was his priority — presenting a fair hearing.''

''I don't think anyone was happy with the hearings. I think then-Sen. Biden was surprised by the way the Republicans went on the attack,'' Hogan added. ''It wasn't that he didn't take sexual harassment seriously."

Not calling Wright to testify was part of the political miscalculation, Hogan says. Committee lawyers and Wright's attorneys decided that she'd be saved her own public humiliation by providing written testimony, copies of which Hogan recalls handing out to reporters at the time. Not having Wright in front of the cameras, though, limited the impact and led to the accusations that Biden had kept her away.

''The only thing I blame him for is that I think he should have called the other witnesses,'' said Mary Frances Berry, the former chairwoman of the United States Commission on Civil Rights, and one of the people who led the charge against Thomas.

Asked for comment about the hearings, the vice president's office referred to an interview Biden gave to journalist Jules Witcover for Witcover's 2010 biography of him.

“There's a myth that's grown up that we somehow denied her," Biden said in that interview. "We had her in town to testify, we expected her to testify, we prepared her to testify; she chose not to testify. She had her own reasons. I don't know exactly what they were. And people say, 'Well, why didn't you have her testify, anyway?' Well, that's like calling a hostile witness in a case." Wright did not respond to a request for comment.

"It's been quiet for a long time, but it'll be back in the limelight if he gets in the race," said Eve Moreland Stacey, another founding member of the I Believe Anita Hill group. "Especially against Hillary."

Hogan said the attacks on Biden not only misunderstand what happened in 1991, but all the work he's done on behalf of women since, including leading the charge for efforts against campus sexual assault, such as the event he headlined at Ohio State. "The next 24 years have shown who he is, especially his record as the driving force behind the Violence Against Women Act," she said.

“Certainly the vice president as a senator was very good on certain aspects of things that might be termed women's rights —the Violence Against Women Act, he was pro-choice — but sexual harassment is something that affects women across race, religion, socio-economic status," said Deborah Glick, a member of the New York State Assembly from Manhattan. "He should have had an expert panel, and he didn't, and that created a very hostile environment yet again.”

Glick was blunter on Twitter a few weeks ago, when Biden first starting ramping up his exploration of a presidential bid.